Cppo is an equivalent of the C preprocessor targeted at the OCaml language and its variants.
Its main purpose is to provide simple macro substitution (#define) and file inclusion (#include) for the occasional case when this is useful in OCaml.
The implementation of cppo relies on the standard library of OCaml and on the standard parsing tools Ocamllex and Ocamlyacc, which contribute to the robustness of cppo across OCaml versions.

GODI bundles the Ocaml compiler with a large list of add-on packages, and serves as a development platform for Ocaml applications. GODI makes it very easy to install open source libraries for all kinds of development areas on your computer. It is intended as a daily toolkit for developers who are mainly interested that the libraries can be pulled into their own projects effortlessly, and do not want to spend half of their life for figuring out how to configure and build software they haven't written themselves.

Katmake is an GNU automake-like utility for the OCAML language.
It is designed for generating Makefile for OCAML language. You give it a `Makefile.am' describing the project as input and it produces a Makefile. This Makefile is able to build all the project, to perform or to remove the installation, to build the distribution and to remove temporaries files.

OASIS can integrate configure, build and install systems in their projects. It helps to create standard entry points in the source code build system and allows external tools to analyse projects easily.
It is inspired by Cabal which is the same kind of tool for Haskell.

This is a simple implementation of `expect` to help building unitary testing of interactive program.
You can match the question using a regular expression or a timeout.
See the Expect manual for more information:
http://expect.nist.gov/

An ocamlbuild plugin that supports compiling C and C++ cross platform
using ocamlbuild only.
Variant builds - can build many different variants from the same
source tree. For example static libraries, test builds, debug,
optimization, linking or not linking with some other code, different
platform builds etc.
Automic recursive header file generation - needed for pulling source
into _build directory.
It used to be able to rebuild on header file change, but it has
regressed - it is possible that .stamp files do not hold signatures of
dependencies of dependencies or something.
It has not been tested on Windows, but build rules have been copied
from old build scripts so it should not be that hard to get going.

OCamlify allow to create OCaml source code by including whole file into OCaml string or string list. The code produced can be compiled as a standard OCaml file. It allows embedding external resources as OCaml code.

ODLL is creating a Win32 DLL from an OCaml library, and automatically generating the C stubs needed to interface the OCaml code and the C code and the .H interface. Simply run ODLL with you CMA/CMXA and one or several CMI interfaces and ODLL will do the job for you.

This is a meta build system.
It is implemented as an ocamlbuild plugin.
It checks out source code from repositories and starts builds of
individual components.
Because ocamlbuild doesn't support linking additional files, a lot of
different code is collected in a single file. This includes a JSON
parser for configuration files.
Symbiosis tries to avoid the problem of collecting all source
dependencies in one large tree, or alternatively installing
dependencies on the system. The former makes it difficult to change
dependent component versions. The latter makes it difficult to quickly
test different build version complicates developer setup.
Correctly configured, just call ocamlbuild with a target for the top
most component to build. All the source should be appear in the
working directory and build.
Initially it can be complex to set up, but once done, it is rather
easy to add new components with interesting dependencies.